Process of regenerating zeolites



Dec. 21 1926. 1,611,422

E.G.DUDEN PROCESS OF REGENERATING ZEOLITES Filed July 5. 1925 RAW WATER TO BE TREATED AW WATER 4 3 7 RAW wA-r-ER FOR wnsnuve 37 TREATED 7 q was? A;

INVENTOR Patented Dec. 21, 1926.

UNITED STATES PATENT OFFICE.

' EMIL G. DUDEN, OF OAKMONT, PENNSYLVANIA, ASSIGNOR. TO WM. B. SCAIFE & SONS COMPANY, OF OAKMON'I, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

PROCESS OF REGENERATING ZEOLITES.

Application -filed July 3, 1925. Serial No. 41,355.

Thisinvention relates to the regeneration of zeolite beds used for water softening.

An object of the invention is to more ef fectively apply regenerative solutions to zeolite beds. Another object is to introduce regenerative salt solution to zeolite beds 'contained in a tank in such manner as to avoid undue dilution of the salt solution, and without the necessity of emptying the tank before introducing the salt solution. Another which a measured amount of salt solution may be applied directly to the top of the zeolite bed, and immediately drawn throughthe bed, with a minimum amount of dilution, and without having to empty the tank containing the zeolite. Another object is to provide a new, more efficient, and more compact unitary apparatus for softening water by passing it through zeolite beds, for wash ing the zeolite by reverse flow of raw water,

and for regenerating the zeolite by applying a proper measured amount of salt solution directly thereto, without the necessity of any apparatus other than that contained in the unitary system described.

Other objects,uses, and advantages will be apparent to those familiar with the art from a reading of the following specification and a study of the drawings accompanying it. Referring to the drawings there is illustrated a complete unitary softening apparatus'comprising a main tank 1, having a strainer screen or manifold 2 positioned across it near the bottom and retaining thereon a mass of zeolite 3, filling approximately three-fourths of the tank. A draw-off pipe 4 leads from the bottom of the tank below the screen 2. This draw-off pipe 4has a lateral extension which leads to afour-way union 6 from which leads a second pipe 7 ontrolled by a valve 8, in which is positioned a meter M for measuring the amount of softened water taken from the tank by means of the pipe 4.

The tank is closed at the top except for a central outlet therein formed by an attached fitting, comprising a tubular portion 10 to which is attached a casting 11, through the top of which extends a pipe 12, the pipe 12 and casting 11 having a water-tight packing 13 therebetween. The pipe 12 extends downward through the tubular member 10,

and is of such outer diameter that a passage 14 is provided between the pipe and fitting,

leading into the main tank. The lower end of the pipe 12 has a perforated distributor head 15, and its outer end has a laterally and then downward extension, leading to a three-way valve 16. I

The casting 11 forms a chamber 17 ,into which leads a pipe 18, from a three-way valve 19. Beyond the valve 19 a pipe 20 extends to the union 6 above referred to. Also leading off from valve 19 is a lateral pipe 21, leading to T-connection 22, from which leads a pipe 23, running to a water main or other source of constant raw water supply. The third branch from the T-connection 22 is a pipe 24, leading to a T-connection 25, from which also leads off a pipe- 26 controlled by a hand-operatedvalve 27 and extending through the cover 28 of a saltcontaining tank 29. Just below the cover 28 and inside the tank 29 the pipe 26 is controlled by a float-operated valve 30.

From the-T-union there leads ofi a pipe 31 controlled by the hand-operated valve 32, to an eductor E. 'The outlet of this eductor is a pipe 34, leading to a sump S, from'which leads a sewer pipe 33. From one side of the eductor E a pipe35 leads to a threeway valve 36 from which also leads pipe 37 to the connection 6, above referred to, and a third pipe 38, leading to a T-connection 39, into which also leads the pipe 18 above referred to, and a third pipe 40, connecting the union 39 with the three-way valve 19.

From the three-way. valve 16 above referred to there extends a. pipe 45, the lower end of which passes through a packing 46 in the wall of the tank 29, and terminates in a strainer extension 47 extending across and positioned near the bottom of the main compartment A of the tank 29. The threeway valve 16 also controls a third pipe 48, which extends through a packing 49 in the Wall of the tank 29. The pipe 48 extends into the compartment A and upward .through a packing 50 in the bottom 51 of a supplementary compartment B built into the tank 29. The tank or container 29 seats 'upon a table T, or any other suitable form well known. Raw water is passed through a zeolite bed, giving u lime and magnesium in exchange for so ium from the zeolite. After a certain amount of water has passed through, this exchange ability of the zeolite becomes reduced, and it is necessary to revive it by treatment with a salt solution. When so treated the zeolite surrenders the lime and magnesium in exchange for the sodium from the salt solution,,and is ready to repeat the cycle of water softening.

It has been customary in the regeneration of zeolite beds, where they are contained in closed tanks, to simply introduce the salt solution diluted as it enters the tank, and allow it to pass through the zeolite in the way that the raw water ordinarily does. This results in a great dilution of the salt solution, consequent slowing up the regenerating action, as well as a waste of salt. Another Waythat has been used, is to drain the tank, and then add a dilute salt solution to the zeolite bed, but this requires a comparatively large amount of time and labor.

By the process and apparatus herein described it is not necessary at any time to drain the tank, the salt solution is applied directly above the zeolite bed, without material dilution, passes immediately into the zeolite and downward therethrough. It comes into immediate contact while at maximum strength with that portion of the zeolite that is most spent. Consequently the rapidity of regeneration is increased by this mode of application of the salt solution. Practically no manual labor is required to practice the regenerating process described, with this apparatus.

The operation of the apparatus illustrated is as follows:

The compartment A of the container or tank 29 is kept nearly filled with salt. This salt is kept covered with water, the water being kept at a constant level by means of the supply pipe 26, which leads to the constant water supply pipe 23. Valve 27 is normally left in open position, and float control valve 30 permits water to flow into compartment A until it reaches the desired level and then shuts it ofi, as will be readily understood by those familiar with this art.

Compartment B of container 29 is watertight, and is entirely separated from the compartment A. When compartment B is emptied, andthe valve 16 is thrown so that pipe 12 is shut off. and pipes 48 and 45 connected, brine will flow from the compartment A- through the strainer head 47, through the pipe 45, valve 16, pipe 48, into the compartmentB until the level of brine In compartment B reaches the normal level of water in the compartment A. Float valve 30 will permit water to be added to the main compartment A as fast as it is drawn off and supplied tocompartment B so that automatically with the valve setting as just stated the compartment B will be filled with water that has passed throu h the salt contained in compartment A. hereafter valve 30 will be closed automatically.

When the apparatus is in normal operation, raw water from pipe 23 passes through the union 22, pipe 21,. valve 19, pipe 40,

union 39, pipe 18 and into the top of the tank throng the fitting 10. The tank is normally full of water, and treated water is drawn off at the bottom thereof through the pipes 4, union 6, pipe 7, and meter M to the point of use. In this normal operation the valve 32 is closed, the valve 19 is set to shut off the pipe 20, but to permit water to flow from pipe 21 to pipe 40. Valve 36 is set to close the ipes 37 and 38.

After the so tening bed 3 has been used for a normal period of time, and needs washing and regeneration, valve 19 is moved to close pipe 40, and to permit passage of water from pipe 21 to pipe 20; valve 8 is closed, and raw water for washin is thus caused to flow in reverse direction through pipes 20 and 4 into the bottom of the main tank. It flows upward through the zeolites, carrying off solid sediments, out through pipes 18 and 38 to valve 36, which is positioned to shut off pipe 37 and to permit water to pass from pipe 38 to pipe 35, through the eductor E and hence into the sewer.

After this reverse flow of raw water has continued sufiiciently to wash the zeolite, valve 19 is closed as to all of its passages, valve 32 is opened, thus permitting raw water to flow through eductor E and out to the sewer. Valve 36 is thrown into position to shut of). pipe 38, and to rmit flow from pipe 37 to pipe 35. Valve 8 is closed. The eductor will thus draw water through the pipes 35, 37 and 4 from the bottom of the main tank. At the same time valve 16 is moved to close the pipe 45 and to permit flow of brine from the compartment B through pipe'48 and pipe 12 to the distributor head 15, positioned just above the level of the zeolite bed. Suction of eductor E will draw brine from-compartment B into the main tank, and pipe 12 and distributor '15 will deliver it just above the upper surface of the zeolite. The brine passes immevalve 16 is restored to normal position, shutting ofi supply of brine from the pipe 12, and permitting water in the compartment A to pass downward through the salt therein and up into the compartment B until it is again filled with the saturated salt solution. The remainder of the valves are again restored to their normal positions above described, which results in a flow of raw water into tank 29 through pipe 18, and this may be drawn off as desired through the meter M by control of the valve 8.

I claim:

1. The process of regenerating zeolite in a tank comprising the supplying of salt solution directly to the zeolite underneath a head of water and drawing the solution directly into and downward through the zeolite without first removing raw water from the tank.

2. In water softening systems comprising a zeolite bed, the process of appl 'ng saturated salt solutions immediately adi acent the surface of the zeolite and drawing it through the zeolite in the normal direction of flow of water being softened. 7

Y 3. In water softening systems comprising a zeolite bed, the process of ap lying saturated salt solutions immediately adjacent the surface of the zeolite underneath a head of raw water and. drawing it through the zeolite in the normal direction of flow of water being softened.

In testimony whereof, I sign my name.

EME G. DUDEN. 

